Generally, a display unit such as an LCD and a manipulating unit such as a volume control unit are disposed on the front of an escutcheon provided on front of an acoustic device. Members are provided for holding on the back of the escutcheon the LCD and volume control unit in position in the device and/or on a wiring board.
As an example of such an acoustic device, a car stereophonic device as shown in FIGS. 7 and 8 is known. In this car stereophonic device, an escutcheon 32 is attached to the front of a device casing 31. An LCD panel 33, a cassette tape insertion dust-proof door 34 and a knob 35 to adjust the sound volume, tone and balancing by turning the knob are attached to the escutcheon.
In this device, a conventional structure which fastens an LCD 36 and a volume control unit 37 is proposed as shown in FIGS. 9 and 10. A plate-like front chassis 38 is provided on the back of the escutcheon 32 in parallel relationship thereto. A pair of holes 39 is provided in an upper portion of the front chassis 38 to pass therethrough the corresponding volume control units 37. An opening (not shown) is provided in a lower portion of chassis 38 at a position corresponding to that of the LCD 36 to watch the LCD therethrough.
The device casing 31 includes an upper casing portion 31a and a lower casing portion 31b which includes a bottom plate and side plates. A volume baseplate 41 and a main baseplate 42 extend backwardly from the upper portion of the front chassis 38 and from the lower portion of the LCD panel 33 such that they are parallel to the upper casing portion 31a and to the lower casing bottom, respectively.
The volume control unit 37 includes an adjusted volume body 37a, a portion 37b fastened to the front chassis 38, and a manipulating unit 37c connected to the knob 35. The LCD 36 includes the LCD panel 33 as the front display, a holding unit 44, a light emitting element 43 for transparently illuminating the LCD panel 33 and a terminal 45 provided on the holding unit 44. The terminal 45 is provided in the form of an L so as to cover the lower end of the panel 33 and a forward part of the bottom 42.
The LCD 36 and volume control unit 37 are fastened such that the LCD panel 33 is disposed in a cutout 40 in the lower portion of the front chassis 38. The holding unit 44 is disposed behind the LCD panel 33. The LCD panel 36 is connected at its lower end to the main baseplate 42 through the terminal 45. The body 37a of the volume control unit 37 is attached to the underside of the volume baseplate 41. The fastened portion 37b of the volume control unit 37 extends through the hole 39 in the front chassis 38 while the manipulating unit 37c protrudes forwardly through the escutcheon 32. By tightening a nut 46 against the fastened portion 37b, the volume control unit 37 is fastened to the front chassis 38.
However, the structure which fastens the LCD holder and volume control unit requires many volume control unit fastening members such as the front chassis 38 and volume baseplate 41 and hence the steps of fastening those members. In order to securely fasten the volume control unit 37 at a position spaced from the main baseplate 42, a troublesome process for tightening the nut 46 against the plate-like front chassis 38 is required. Thus, generally, in the prior art, the number of parts assembled and the number of steps of assembling the parts are large and complicated. Therefore, there is a correspondingly increasing probability that the fact will be a cause of failures and that the manufacturing cost will increase.